Circular relief grinder



May 17, 1938. c. E. WALLING CIRCULAR RELIEF GRINDER Filsd Sept. 5, 19552 Sheets-Sheet l INVENTOR CLYDE E- WHLLING BY cgwuw- Q- ATTORNEYCIRCULAR RELIEF GRINDER Filed Sept. 5, 1935 2 Sheets-Sheet 2 INVENTORCLYDE E- WELL/N5 BY Q M L. Watt.

ATTOR Y Patented May 17, 1938 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates in general to metal working machines and moreparticularly to grinding machines for sharpening milling cutters, hobs,reamers, taps and so forth. Grinding machines of this type embody avertically rotatable wheel adapted to be swung around a vertical axis,so as to permit of spiral tools, such as cutters, taps and reamers beingsharpened between the centres of the machine. However lip or lead angleson tools can be ground with machines of this type only, by laterallyoffsetting the axis of the respective tool with respect to the cuttingsurface of the grinding wheel and then the lip or lead angle isproportionate to the offsetting of the axis of the tool and alsoproportionate to the diameter of the tool.

The above described method of grinding lip or lead angles on tools byoffsetting its axis with respect to the grinding surface of the grindingwheel is complicated and inefficient and does not permit to properlygrind tapered or taper spiral tools, such as spiral cutters, spiraltaper reamers, taper spiral hobs etc., as the outside contour of suchtools is distorted during grinding operations. It has been proposed toovercome the above described deficiency in grinding tapered or taperedspiral tools by swinging the wheel head on grinding machines of the typereferred to around an axis inclined toward the vertical, so that thewheel, when set square with the main slide of a grinding machine isinclined to the vertical at a definite angle of clearance. However suchinclined mounting of the grinding head limits the use of grindingmachines thus equipped and effects a change in the size of the lip angleon straight tools proportionate to their diameter and on spiral toolsproportionate to their diameter and the pitch of the spiral.

It is the general object of this invention to provide a grinding machinewhich permits of proper grinding of all tools, including taperedstraight or spirally fluted tools etc., with any desired predeterminableclearance or lip angle. This desideratum according to the invention isattained by the provision of means for tilting the grinding head of agrinding machine in a vertical plane, so as to permit of the cuttingface of the grinding wheel being set to any desired inclined positionwith respect to the centres of the grinding machine.

With this and incidental objects in view, the invention consists incertain novel features of construction and combination of parts, theessential elements of which are set forth in the appended claims; and apreferred form of embodiment of the invention is hereinafter shown withreference to the drawings accompanying and forming a part of thisspecification.

In the drawings:

Figure l is an end elevation of a grinding machine embodying theinvention.

Figure 2 is a front elevation of the grinding machine shown in Figure 1.

Figure 3 is an enlarged fragmentary sectional view partly in elevationof the machine shown in Figure 1, the section being taken on line 3-3 ofFigure 2, and

Figure 4 is a cross sectional view on line 4-6 of Figure 3.

In the drawings the grinding machine is v mounted on a suitablyconstructed stand I, which stand vertically adjustably supports a bed 2by means of brackets 3. The bed 2, which is vertically shiftable bymeans of a threaded shaft 4 and gearing 5, operated by a hand wheel 6,supports a slide l, longitudinally slidably arranged on said bed. Theslide 1 is longitudinally moved upon the bed 2 by suitable means, suchas a rack bar 8 and gear 9, which gear is rotated by a shaft in having ahand wheel ll attached to its outer end.

A pair of lengthwise adjustable centers l2 and M, one being fixed andthe other being vertically adjustable are supported on the slide l andpermit of axial mounting of a tool below a grinding wheel l5. This wheelis secured to a horizontally disposed spindle l6, journaled in a head I!and will properly grind a tool supported between the centres l2 and it,when the tool is traversed with the slide 1 on the bed 2. The spindle i6is coupled with a motor l8 by means of a pulley drive 19 and the motorI8 is mounted on a bracket 20, which bracket laterally extends from thehead ll. An adjustably mounted tool dresser 2! permits of proper shapingor dressing of the wheel IS.

The wheel head i'l consists of a wheel supporting part 22 and aninverted cup-shaped base part 23, which base part tiltably mounts thewheel supporting part 22. The base part 23 extends with its verticalflange 24 into the recessed top 25 of the stand l and rests thereupon bymeans of a circumferential shoulder portion 26. The top plate 21 of thebase part 23 is radially recessed on an arc in a vertical plane, so asto provide a curved recessed seat 28 for the downwardly extended legportion 29 of the wheel supporting part 22. This leg portion embodiestwo legs 30, which are integrally connected at their,

lower ends by means of a curved plate 3!. The plate 3! slidably restsupon the seat 28 and permits of the part 22 being tilted in a verticalplane with respect to the part 23. A slot 32 in plate 3i, arrangedradially with respect to the curve of said plate, and a central bore 33in the recessed seat 28 of the base part 23 permit of the parts beingtiltably clamped to each other by means of a bolt 34. This bolt engageswith its head portion 35 a perforated integral cross piece 36 within thestand I and thus secures parts 22 and 23 to the stand, when the nut 31resting upon a curved washer 38, fitting the curvature of the plate 3|,is screwed home.

When it is desired to set the head ll and therewith the grinding wheel ifor a particular job,

the nut 31 is slightly loosened so that the base part 23 can be axiallyrotated to the desired position by common means, such as a worm drive,as generally practiced and therefore not shown. The setting of the headcan be read on a scale 38, which scale indicates the horizontal angle ofhead ill with respect to the axis between the centres of the grindingmachine. Then the wheel supporting part 22 is tilted to the desiredangle which can be effected either manually or by any common means, allas well known in the art. The tilting of the wheel supporting part 22with respect to the horizontal can readily be read on a scale 39. Whenall adjustments are made the nut 35 is again tightened and the machineis ready for operation.

Preferably the two scales 38 and 39 are arranged at the same side of themachine and exact readings on the scales can readily be indicated saidstandard, work supporting means adjustably secured to said slide, agrinding wheel shaft, and a supporting head for said grinding wheelshaft, said supporting head embodying a circular base horizontallyrotatably secured to said standard, a bearing means for said grindingshaft and integral supporting means for said bearing means intersectingthe axis of rotation of said base, said supporting means tiltablysecuring said bearing means to said base to effect in every adjustedposition of said base tilting of said bearing means and grinding shaftin a plane through the longitudinal axis of said shaft and the axis ofrotation of said base.

2. A grinding machine as described in claim 1, wherein said horizontallyrotatable base portion of said supporting head embodies an axial boreand is recessed to form a curved seat, wherein said bearing means forsaid grinding wheel shaft is provided with a downwardly extended, curvedportion slotted substantially parallel to said shaft and slidably restedupon the curved seat of said base portion, and wherein a single clampingmeans secured to said standard is axially extended through the bore ofsaid base portion and the slot in said bearing means for rigidlysecuring said base portion and said bearing means jointly to saidstandard.

CLYDE E. WALLING.

